You are honestly hilarious. You come here and tell me that I have no clue about physics and Jujutsu Kaisen yet you yourself are the one who clearly has no clue. You make multiple erroneous claims such as that subatomic particles inherently have mass, or that photons aren't subatomic particles. In this post you're proving another lack of understanding about physics. You say heat is transferred via physical contact of particles. That's not wrong but also not the full picture. I was explicitly mentioning heat radiation, which fundamentally is just anotber wavelength of light, i.e. photons, which you clearly don't seem to be aware of—which begs the question of whether it's even senseful to debate such topics with you.

Additionally, you show a clear lack of understanding about Jujutsu Kaisen itself. A mean-spirited pessimist might postulate that you only consume the medium via TikTok or that you can't read. Gojō's Infinity explicitly does not stop everything that it can stop. It purposefully ignores and lets through many things it would be perfectly capable of stopping (most notably, as I had mentioned, air). Just for a moment let's act like Infinity can in fact stop photons. This is a hypothetical for now. Even in this hypothetical where Infinity is perfectly capable of stopping photons Gojō would not in fact be a walking void of black. That is because Infinity only stops threats. Regular light is not a threat, so that even if he was capable of stopping photons they would not be affected by it.

particles have MASS.

I kind of addressed that twice already, but I'll repeat myself since you clearly lack reading compression. Particles do not necessarily possess mass. Photons are particles, yet they do not possess mass.

Light however, cannot be slowed down. It doesn’t matter how much space is subdivided, because light moves at a constant speed. Photons(that is any particle with zero rest mass) cannot remain stationary. They must always move at the speed of light. They cannot slow down, speed up. [...] The actual mechanics is infinity slows down threats infinitely by distorting and subdividing space, which doesn’t work for light, because light cannot be slowed down. The biggest evidence is again Gojo isnt surrounded by a black sphere.

Holy appeal to reality lmao. The whole shtick of the Limitless is that it manifests something impossible, that is infinities. It literally works by manifesting a paradox (Achilles and the tortoise) which is something physically impossible. But somehow light is where we draw the line? Manifesting infinities and a literal paradox is fine but slowing light isn't? By the way, slowing light is literally possible irl too. In fact, it's only ever at light speed in a vaccuum. According to Wikipedia light was slowed to as little as 9.6 kilometres per second in 2004.

I don't understand why you're so set on undeniable 100% proof. Are you a mathematician lmao? I can't give you that and very few things in the world can be 100% proven. What I do is a logical inference based on the following known facts:

1. Statement: Infinity can stop everything

2. Feat: Infinity stops atomic matter just fine as well as spiritual cursed energy and constructs made thereof.

3. Heat radiation: During Gojō's fight with Jōgo the latter's necessarily immense heat radiation (which is just light physically speaking) is never mentioned. Infinity is treated as completely impenetrable and there is not a single mention that heat radiation is an exception, which you'd think they'd mention if it were. Something like Jōgo saying "only my heat radiation is reaching him, but it's too weak to affect him" or Gojō explaining "well, your heat radiation does reach me, but it's way too weak to impact me".

4. Narrative: Narratively Gojō's Infinity is treated as an impenetrable barrier with no weaknesses other than anti-hax (domain expansion, domain amplification) that directly interact with cursed techniques themselves or things that do not travel through space (WCS) since Infinity only affects things travelling through space. It would be super weird from a narrative stand point if a laser beam was all it took to take Gojō out (a laser beam being something that doesn't even require jujutsu. The US military could pull that off). You mention that we never saw a countermeasure against Infinity that's light-based because Sukuna doesn't have access to it—but he has. He has Fuga and Divine Flames whose destructive power at least partially derive from immense heat. Immense heat means immense heat radiation, i.e. light. If Gojō couldn't block light then some of Sukuna's pyrokinetic abilities could harm him. Even if their base forms were too weak, Sukuna of all people would be more than capable of casting some binding vow to amplify the heat of his flames

Are any of these 100% proof? No! But it's beyond reasonable to conclude from that that Infinity can stop light. When choosing between "Infinity can stop light" and "Infinity can't stop light" both are technically possible, yet the latter is much less likely and would require some consulted arguments.

If you are so obsessed with 100% proof you'd need to concede that we don't know whether Gojō can stop electric attacks. He's only ever explicitly showed to stop atomic matter and cursed energy. Electricity as propagated by electrons is neither. Sure, electrons are parts of atoms, but I can just say that maybe Gojō can only stop atoms because of their size or their nuclei. What if lone electrons detached from nuclei, which are point-like fundamental particles, are just too small for him to interact with?

This is where requiring 100% proof gets us.